Hydro Pumped Storage. It's a good solution when you have lots of excess cheap generation at one time of day, and then inadequate generation at other times of day. Especially if it's difficult to ramp the generation up and down to match load. Instead, you're ramping up and down extra load by turning the pumps on and off. Which is better than just adding load that wastes the energy.I don't know how much it's used, but I read an article about the use of reservoirs for storing water for use in Hyrdro-electric generation. Off peak, water is pumped into the higher reservoir and routed back to the main supply when needed. Very interesting concept.
I think this is the largest one in the country.
Dominion Bath County Pumped Storage · State Rte 705, Warm Springs, VA 24484
★★★★★ · Hydroelectric power plant
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